Ecotoxicology and Ecological Risks of Per‐ and Polyfluoroalkyl Substances

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Per- and polyfluoroalkyl substances (PFASs) are a large group of synthetic chemicals utilized for diverse applications including nonstick coatings, industrial lubricants, fire retardants in clothing and home goods, and as fire suppressors in firefighting foams. Owing to the wide variety of PFAS uses and their resistance to thermal and chemical breakdown, they have been detected in surface and groundwater resources throughout the Nation, which has raised health concerns. The concerns range from human exposure through drinking water to broad ecological effects related to wildlife exposure.

Although there is research on some individual PFASs, data suitable for determining ecological or ecotoxicological risks in prospective or retrospective assessments are lacking for most PFASs. Recognizing these knowledge gaps, the Society of Environmental Toxicology and Chemistry (SETAC) sponsored a workshop in 2019 that focused on the current (2021) state of the science needed to support environmental risk assessment of PFASs.

As an outcome of the meeting, scientists produced a paper summarizing currently available information from around the world needed to understand exposure, and hazards of PFASs in the context of ecological risk assessment. Utilizing this information, the scientists were able to identify critical gaps and uncertainties relative to ecological risk assessments for PFASs and propose approaches to address these gaps.

Proposed approaches include the development of targeted monitoring programs to support exposure assessment and the formulation of predictive models for bioaccumulation. Scientists emphasize development of computer models and laboratory and field methods that efficiently assess biological effects for identification of sensitive species/endpoints. Finally, the scientists discuss the importance of cross‐disciplinary approaches that employ conventional and new methods in an integrated, resource‐effective manner to address needs associated with understanding the ecological risks of PFAS exposure.

There are several critical considerations for assessing the ecological risks of PFASs including development of flexible tools because the spatial scale might range from localized “hot spots” (for example, near fire‐fighting training) to global contamination (for example, from atmospheric transport). Another consideration is the large number of PFASs—more than 4,500 chemicals—that highlights the importance of chemical mixtures, which may include precursors and degradation products, in developing approaches to estimating risk.

This study was funded in part by the U.S. Geological Survey Environmental Health Program (Toxic Substances Hydrology and Contaminant Biology) and various financial supporters of the SETAC Focused Topic Meeting.